Cristian Guzman's final act as the Washington Nationals' everyday shortstop was to slash a double the opposite way. He went 2 for 7 in a twi-night doubleheader, the kind of night that, were circumstances different, might have given a scuffling veteran something positive to build upon heading into the season's final, crucial month. But it's not going to happen, and as Guzman batted for the final time at the end of a long Wednesday night, the videoboard in center field beamed down at him his unsightly batting average: .196.

If Guzman is going to climb his way to the sunny side of the dreaded Mendoza Line, he is going to have to do it as a part-time player, following a trade Tuesday night that, for the Nationals, represented both a painful concession and a reason for hope.

There is perhaps only one team in the majors -- and certainly only one contender -- that can say the addition of Deivi Cruz represents a major upgrade at shortstop. He may be hitting just .268 this season, but that's still 72 points higher than Guzman. And at $800,000 this season -- of which the Nationals are on the hook for only about one-sixth -- Cruz is a bargain, especially when compared with the $4.2 million the team is paying Guzman this year.

Guzman "is not the total reason why we haven't played the way we wanted in the second half, but he could have certainly helped us win a few ballgames in the second half if he had performed close to his standards," Manager Frank Robinson said. "But he hasn't, for whatever reason."

For most of the last five months, the Nationals have been saying they had no other viable alternatives to Guzman at shortstop or slumping veteran Vinny Castilla at third. Now, by game time Thursday night, they will have alternatives to both.

Ryan Zimmerman, who will be called up Thursday from Class AA Harrisburg, needed all of three months in professional baseball for Nationals GM Jim Bowden to determine he is as good as Brooks Robinson, Cal Ripken and Scott Rolen all rolled into one. (Presumably, Bowden's exclusions of Mike Schmidt and Eddie Mathews were intentional.) Meantime, to fix the Guzman Problem, which has bedeviled the team since Day One, the Nationals have imported a shortstop whose body of work looks remarkably similar to that of Cristian Guzman's. Both are decent-field, hack-happy, anti-walk machines who never met a waste pitch they couldn't dribble out to shortstop.

Cruz is a lifetime .269/.293/.390 hitter (batting average/on-base/slugging), while Guzman was at .266/.303/.382 at the start of this season -- before he became possessed by the ghost of Mario Mendoza to the tune of .193/.234/.272. They also have similar approaches to taking pitches: Both players, like clockwork, can be counted on to draw a couple of walks per month.

In the case of Cruz, it seems he has the same aptitude for commercial air travel as he does for plate discipline.

Joining his new team on its most important day of the season to this point -- a pair of games against the division leaders, at a time when the wild-card lead is also within view -- apparently wasn't a big enough priority for Cruz to arrive early enough at the airport to ensure he caught his flight. He missed one flight for unknown reasons, then missed a second because he was stuck in the security line, according to team officials.

"He's missed a couple of flights," Robinson grumbled between games. "I don't have any idea where he is."

Cruz's absence notwithstanding, the Nationals made sure to point out that he would be eligible for their postseason roster, since the deal was completed before the midnight Aug. 31 cutoff.

The Cruz move was an acknowledgment, however belated, on the part of the Nationals' front office that the Guzman signing was a bust. The delay, even as the media and fan base were screaming for a change, was understandable, given the fact the Nationals had $16.8 million invested in Guzman and still have three more years of his servitude to look forward to.

"He still has a four-year contract," Robinson said, "so if you're going to give up on him now, what are you going to do for the next three years? So you've got to try to keep him alive and keep him going."

One wonders whether Guzman understood, as he stood out at shortstop and kicked at the dirt at his feet, that it was his last day as the Nationals' everyday shortstop this season. Robinson said he had not talked to him about the change that was in the works, and Guzman declined to talk to reporters.

As the Nationals bounded off the field following their 4-3 win in the nightcap, Guzman was front and center, his shirt untucked, a big grin on his face, like he had not a care in the world.